CO2 concentrations (ppm) have increased significantly in recent years, increasing by 10ppm every five years. For example, Carbon dioxide concentrations increased from 310ppm to 320ppm between 1960 and 1965. CO2 levels in the atmosphere have risen dramatically in recent years and continue to do so at an alarming rate. CO2 has a long enough life in the atmosphere to diffuse fairly equally over the globe. As a result, observations taken at a particular location (such as Mauna Loa) can be used to estimate world average CO2 concentrations. The increase in carbon dioxide concentration is because people worldwide are releasing carbon dioxide into the atmosphere, primarily through the burning of fuels like charcoal, petroleum, and gases. (Miller et al, 2008)

b.) About nine gigatons of C per year enter the atmosphere from the burning of fossil fuels, yet atmospheric concentrations only increase by about four gigatons of C per year? Where does the rest of the fossil fuel-derived carbon dioxide go?

During warmer seasons, plants use the remaining five gigatons of fossil fuel-derived carbon dioxide, along with sunlight and moisture, to make foods and other substances they need to develop through a process known as photosynthesis. This could result in significantly lower Carbon dioxide concentration in the atmosphere.

2.)

a.)  The Deer Island Sewage Treatment Plant removes many contaminants from sewage before the effluent is released to the ocean. Describe how primary treatment works and what contaminant(s) this process removes from the sewage effluent. Describe how secondary treatment works and give examples of what contaminants this separate process removes from the sewage.

Primary treatment works as follows: Flows run into grit chambers upon pounding, which extracts grit for dumping at the landfill. Following that, inflows are sent to first processing clarifiers, which eliminate close to half of the contaminants present in common effluent (55-65 percent of total suspended solids and up to 51 percent of pathogens and poisonous pollutants are removed). Gravity removes sediment and froth from wastewater in this process. The top purifiers of the factory are 184 feet in length, 39 meters in width, and 25 feet underground. The clarifiers have a “piled” settlement area in the midsection to maximize the settle capability of the tanks that are crammed into Deer Island’s limited space.

The secondary treatment eliminates non-settle able materials through biological and gravitational treatment using secondary treatment mixers, reactors, and clarifiers. The biological system is an oxygen-activated sewage system that depends on organisms to digest organic material that remains in the effluent. The level of pollutant removal is increased to above 85percentage points after-treatment processes.

b) This engineering solution to cleaning up Boston Harbor costs about $5 billion. Describe how this cost for the sewage treatment upgrade can be justified to the MWRA ratepayers who paid for the cleanup. In other words, how is the value of a clean Boston Harbor now worth the $5 billion cost?

It created an economic assessment model centered on the societal worth of services that healthy ecosystems may deliver. It operates by assessing each ecosystem’s overall worth in a study region such as beachfront, salt marshlands, and vernal pools within the case of Boston Harbor and considering each type of land cover in the area. The value of safe water, for instance, incorporates the ability to support fishing grounds and coastal recreational opportunities and activities.

     3) a.) A kiddie pool has a surface area of 5 m². A brief, intense rainstorm dumps 10 cm (0.1 m) of rain in the water directly into the pool. How much does the volume of the pool increase? Show your work.

T.S.A. = 2πrh+2πr² 

V= πr²h

5 m²=2(3.14r²) h

5m²= (6.28r²)0.3m

5m²=1.884r²

5m²/1.884=r²

2.564m=r²

1.60125m is the radius.

The volume of rainwater in the pool

V= (3.14)2.564

V= (8.501m²)0.1m

V=0.8051m³

The volume of the pool increase?

2.1453m³-0.8051m³

The volume of the pool increase is 1.3402m³

b) The kiddie pool is 30 cm deep. What is the volume of the pool? 

       V= πr²h

V= (3.14)2.564m

V= (8.051m²)0.3m

V=2.1453m³

c)Now, assume that evaporation from the pool is about 2 cm per day and that you fill it with a slowly dripping faucet to maintain the same water level (e.g., the water level is at a steady-state). What is the residence time of water in the kiddie pool concerning evaporation? (2 points)

2.1453/2=1

The residence time of water in the pool after evaporation is 1 hour

d) Annual rainfall in New England, including the Parker River Watershed, is 130 cm/yr. The Parker River Watershed is 200 km² in area. How much water from rain (which drains the entire watershed) flows down the Parker River each year? Please assume all the rainwater ends up in the Parker River. Show your work. Hint: It might help to draw a picture of this annual rain on the land.  Hint 2: Make sure your units are converted to be consistent.

200km²

Area=LW

200/130

=1.5

e.) If climate change increases annual precipitation rates across New England, how will this change the water residence time in the Parker River Watershed? Increase, decrease, or stay the same. Please explain your answer.

The residence time of water in the park river watershed will increase. This is because this climate change causes more rainfall in the New England which deliberately increases the level of water in the Park River Watershed.

4.) Ecosystems

a.) Please design a sustainable ecosystem. Start with a household bottle. Describe (you don’t have to make it) what you put in it? Then seal the container. Describe the organisms that you place inside that occupy at least three different trophic levels.

Inside the household bottle container, I have put water, algae, snails, and fish. In this ecosystem, fish lives in water as their habitat; fish feeds on a snail, snails feed on algae.

b.) How long might your ecosystem might last until some irreversible changes would be observed?  In other words, what might change that would prevent the survival of one of your species of organisms? If you say “forever,” what would you change to kill off one of your species?

If in this ecosystem all the water evaporates, fish will not survive as their habitat is water. It will die.

c.) Explain how carbon and oxygen levels might vary with season and explain why.

During a year, the amount of Carbon and oxygen contained in the atmosphere changes. Plants are important in the carbon cycle, which accounts for a lot of the variance. Respiration occurs throughout the year, but it is more prevalent during the winter months, leading to increased CO2 levels in the atmosphere.

5.) a.) Describe three adaptations that Sargassum has developed to survive in the open ocean.

• Sargassum species feature a heavily branching thallus containing hollowed berrylike rafts known as pneumatocysts that are primarily filled with oxygen gas. Pneumatocysts provide the plant structure buoyancy, enabling it to float on water.
• They have rhizomes, which seem to be horizontal stems that enable species to resist the tugging of oceanic currents. Flexible blades sprout upward from the rhizome to hold the vegetation to the seafloor as the plant grows downwards from the rhizome to hold the plants to the seabed.
• Sargassum rafts float in the seawater for miles. Fishes, marine turtles, seabirds, crustaceans, prawns, and other species find food, habitat, and perfect breeding ground under this aquatic ecosystem. Many species, like the seaweed (frogfish), lives in this habitat. Sargassum is a major nursery region for commercially important species like jacks and amberjacks.

b.) How does Sargassum get nutrients to support its growth?

Due to this aspect, seaweeds, unlike land plants, have no genuine stems, roots, leaves, and vascular tissues (tissues that transport moisture, sap, and nutrients). Sargassum utilizes its blades (the seaweed’s ‘leaves’) in absorbing nutrients from the surrounding water.

c.) What happens when a Sargassum “bloom” is washed ashore?

When Sargassum washed up on the shore and starts to decompose, hydrogen sulfide (h2s), a gas that smells like rotten eggs – is emitted. “It’s a wonderful vegetation in the ocean, but it’s a poor flora on the beach.”

It has the impact of depositing seaweed onto our shores, with piles of sea grass emerging almost overnight. This seaweed traps garbage on the seashore, deteriorating the environment for tourists and marine life.